High-pressure hose



SPf 2, 1930- M. LoUGvHx-:AD 1,774,983

HIGH PRESSURE HoslE Filed June 21. 1926 Patented Sept. 2, 1930 UNrrED STATES vpaxillaNil OFFICE MALCOLM LOUGHEAD, OF DETROIT, MICIIIIGAN, ASSIGNOR TO HYDRAULIC BRAKE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF CALIFORNIA HIGH-PRESSURE HOSE,

Original application filed J'uly 10, 1925, Serial No. 42,850. Divided and this applicationy ledvJ'une 21V,

` 1926. SerialNo. 117,345.

pressible liquid from a. power cylinder tov work cylinders in an automobile braking system shall be substantially non-expansive under the pressures encountered in thc operation of the vehicle brakes. The hose heretofore commonly used in practice for this purpose is provided with an internal metallic lining made of a coil of wire, which coil is Inserted in the hose by applyingr a pressure to the hose much higher than that expected to be'encountered in the operation of the brakes, then insertingthe coil and permitting the hose to contract around the coil of wire when the pressure is relieved. Such a hose is satisfactory so long as the brake pressure remains below that at which the hose may be expanded away from the outside of the coil of wire. The reason that such a hose is non-expansive under ordinary conditions is that the rubber of the hose is normally under stress against the outside of the coil of wire and does not change its position to leave the coil and thus enlarge the passagethrough the hose until the pressure has exceeded that represented by the natural compression of the rubber against the wire spring.

The object of my present invention is to provide a hose which shall be substantially non-expanding throughout a wider range than that above described and which has been heretofore used for braking purposes. ln accordance with my present invention-I utilize a hose'which is provided with a coiled .wire insert which lies embedded -Within the hose, preferably between two layers of fabric therein, this wire restricting the expansion of the. hose under liigh pressure to a much greater degree than if the hose were constructed of rubber and fabric without the embedded coil of wirc.- Within the passage through this hose I place a coil of spring wirewhich, by ther process hereinafter de scribed, is caused to contact with extremely high pressure against the inner Walls of the hose, thus squeezing or'compressmg a portion ofth'erubber and fabric hose between the two coils'of Wire, that embedded in the ing thei nner coil of wire within the hose;

Figure 3 is a section through the hose inserting member taken on the line 3 3 of Fig. 2, and

Figure 4 illustrates the machine for use in inserting the tool and coil of Fig. 2 within tbe hose. My invention can be best understood `by `following out the process bywhich the hose 'I0 is constructed. The length of hose provided with a coil of reinforcing wire embedded in rubber 7 between the layers of fabric 8 isl first attached to two 'coupling members, the openings through -the end of the coupling'l members being substantially the same size as the normal opening through the hose. A coil of spring wire of suflicient length to extend throughout the length of the hose and into the coupling members at each end thereof is placed upon a two-part mandrel, eac-h end ofthe spring wire eoil being turned inwardly, the mandrel being` provided with a longitudinal slot or kcyway for receiving the turned-in ends of said wire. This mandrel, 35 as shown in Fig. 2, is 'composed lof' two parts l() and 1i, the mating ends of which are provided with registering slot and driver to prevent undesirml' relative rotation of the two parts. The keyway 12 extends into each of 9o the registering parts 1() and 11 for av total distance substantially equal -to the length of the coil spring to be inserted in the hose. After the parts 'l0 and 1l have been inserted into the coil spring from the. opposite ends thereof, they are rela-tively rotated while the driver and slot connection is held out of registry until the spring has been tightly Wound about the mandrel. 'lhereupon the parts 1 0 and 11 are pushed together to a posi- 10o member l5 (Fig. 4,) the portion of the mandrel 11, havingthe slot or keyway therein, extends entirely through and beyond the coupling member attached -to the otherend l of the section of hose into which the spring is to'be inserted. A fixture 16 having an opening 17 therein of greater length thany the full length of the hose is arranged to receive the fitting on the end of the hose remote from the packing glandhthe assembled mandrel with its coiled spring extending into the opening 17 of the fixture 16. After the parts have been thus assembled, the. valvey 19 is opened and fluid under extremely high pressure is admitted to the hollow por-tionof the K fixture 17 and to the interior of the closed section, its escape being blocked by the packing gland 14 which surrounds the end of the o portion 11 of the mandrel. rl`he fluid thus applied through the valve 19 expands thc hose 20 and at the same time assists in forcing the mandrel and its surounding coil of spring wire into the hose to a position at which the end of the spring wire enters the recess 21 in the end of the thimble of the coupling 15.

'If the pressureproduced by the fluid entering through 19 is insufficient to slide the portion 11 of the mandrel through the'packing gland, it may be assisted by the application of a pulling force on the protruding end of the mandrel. a

When the mandrel and spring have arrived at the position at which the spring abuts the recess 21, the portion 11 of the 'mandrel is pulled on for a sufficient distance to cause the portions 10 and 11 of the' mandrel to spread `out their driver and slot connection. This frees the part -10 of the mandrel which then rotates rapidly under the influence of the spring and permits the spring to become expanded within the bore of the hose, which itself is now expanded under the influence of the pressure from the valve 19. The valve 19 is now closed and the portion 11 pulled outwardly a-` ,suricient distance to relieve the pressure Within the hose, whereupon the hose contracts firmly aboutthe expanded spring n wire coil. The packing gland 14 is now removed /from the coupling member 15 and v the opposite coupling member is removed from the fixture 16, whereupon the members 10 and 11 may be oppositely removed from the hose section.

A hose made b y the process just described exhibits very nearly uniform non-expansive characteristics up to extremely high pressures, since the inner coil or wire has been expanded by its own unfurling action against the wall of the passage through the hose at a time when the hose is expanded to the most extreme size to which it is capable of being safely expanded by the fluid pressure therein delivered from the fixture 16. Within a short time the inner coil becomes bonded to the rubber lining of the hose and thereafter all further tendency of the inner coil to expand is overcome by this bonded union between the coil and the lining. This adherence of the lining to the inner coil becomes so firm that the inner coil actually becomes in effect a reinforcing mem-l ber for the fabric body of the hose and tends to prevent expansion thereof under fluid pressure. lVhen the hose is in use, it will withstand an extremely high pressure before the rubber constituting the inner lining of the hose is pressedv away from the outer wall of the spring, and even when pressure is applied as is capable of pressing the hose away from the'outer wall of the spring, the second coil of wire embed-ded between the fabrics of the hose prevents further expansion until Subst antially the break-down pressure of the hose has been reached. A hose constructed as shown in Fig. 1, and not provided with the inner coil spring, is necessarily somewhat expensive because of the vprice of the rubber which lines the passage through the hose, but when provided with an expanded spring lining by the process described herein, the expansion under all pressures' less than the break-down pressure of the hose becomes substantially ne ligible.

Although have fully described the method of making the hose I have done so merely to better explain the construction of the hose. I have not herein claimed the method of makin g the hose since this forms the subject matter of my co-pending application, Serial No.' 42,850, filed July 10, 1925, of which this application is a division.

I claim:

1.- A substantially .non-expansible hose for fluid under pressure comprising an expansible tube adapted to sustain the entire bursting force exerted by fluid pressure, and a coil spring within said tube having closely spaced convolutions, saidl spring being compressed to a diameter smaller than its normal diameter and exerting an outward force upon said tube sufficient to maintain said tube expanded to an amount as great as the amount of expansion said tube would assume under the maximum fluid pressure to which said hose willv normally be subjected.

I2.* A substantially non-expansible hose for fluid under pressure comprising a rubber and fabric tube adapted to sustain the entire bursting'force exerted by the fluid, and a coil spring within the tube exerting an outward pressure on the walls of the tube due to an unfurling action of said spring, the pressure exerted by said spring on said tube being as great as the maximum fluid pressure to which said hose will normally be subjected in use.

3. A'substantially non-expansible hose for uid under pressure comprising a rubber and fabric tube, reinforcing means in saidtube,

said reinforcing means adding strength to' said tube without rendering said tube nonexpansible, and a coil siring'within the tube and exerting an outwar ressure on the walls of said tube due to an un urlin action of said spring, the pressure exerted y said spring on said tube being as great as the maxlmum fluid pressure to which said hose will normal- 1y be subjected in use.

In witness whereof,

m name this 16th da. offJun'e 1926.

y' MALcoLM LUGHEAD.

I, hereunto subscribe 

